Telegraph transmitter



Feb. 8, 1955 T. l. PRzYsn-:CKI

TELEGRAPH TRANSMITTER Drginal Filed Sept. 16, 1952 4 Sheets-Sheet l INVENTOR THEODORE l. P RZYSIECKI BYZ-b ATTORNEY Feb. 8, 1955 T. PRzYslEcKl TELEGRAPH TRANSMITTER 4 Sheets-Sheet 2 Original Filed Sept. 16, 1952 INVENTOR THEODORE l. PRZYSIECKI ATTORNEY Feb. 8, 1955 T. l. PRzYslEcKl 2,701,822

TELEGRAPH TRANSMITTER original Filed sept. 16, 1952 4 Sheets-sheet s INVENToR THEODORE I. PRZYSIECKI ATTORNEY Feb. 8, 1955 TELEGRAPH TRANSMITTER Original Filed Sept. 16, 1952 T. l. PRZYSIECKI 4 Sheets-Sheet 4 INVENTOR THEODORE I. PRZYSIECKI HPM.

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ATTORNEY United States Patent C) TELEGRAPH TRANSMITTER Theodorel'. Przysiecki, Park Ridge, Iil., assignorto Teletype Corporation, Chicago, Ill., a corporation of Delaware Original application September 16, 1952, Serial No. 309,755. Divided and this application November 23, 1953, Serial No. 393,635

8'Claims. (Cl. 178-17) This application is a division of applicants copending application Ser. No. 309,755 filed September 16, 1952.

In printing telegraph `communication systems it is desirable for called stations to respond automatically to an inquiry signal for the purpose of verifying the accuracy ofthe line connection by sending back to the calling station its identification signal or other intelligence message according to a prearranged denotation. The. present invention concerns itself with the provision of auxiliary mechanism for installation upon existing classesfof automatic telegraph printingequipment which will accomplish the transmission of such identification signals in response to calling station control.

A principal object of this invention is to provide4 an auxiliary automatic telegraph signal transmitting apparatus which will respond to an identification inquiring signal incoming overthe line Aby causing to be generated a series ofprearranged identification or other intelligence signals indicative characteristically of the called stationy and at the same time effecting certain supervisory regulation such as preventing the operation of the keyboard equipment and the. generation of calling station answer-back signals during-the interimxin which the automatic identification of the called station is performed.

Another object of this invention is to produce an auxiliary message transmitting apparatus wh1ch 1s automati-l cally responsive to incoming fline signals inaccordance with ya pre-established sequence of operations andv by set' ting up safeguards against-interference with or mutilation of automatic answer-back or identification messages as..v may result from attempts atlocal keyboard operation durf ing the interim of the vautomatic response.

Still further objectsof the present invention will reveal themselves during the course of' the following detailed' description having reference totheannexeddrawings. in

which .likereference numerals have been employed to.

designate-corresponding vparts throughouLand in which: Fig. l is an exploded perspective view diagrammatically illustrating certaintportions .of a -conventional keyboard. transmitting apparatus. having applied theretotvarious fea-.

tures ofthe present. invention; n

Fig. .2 is a fragmentary s1de-sect1onalv1ewvof certamof the: apparatus illustratednin .Fig .1;

Fig.. 3 is a fragmentary planview of the. apparatus :illustratedinFigs. l and 2,...

Fig. 4 is an exploded perspective View of certainof thev operating and control levers detached from the adjacent apparatus;

Fig'. 5 is a fragmentary perspective'view of certain p'or-` tions of the selector. mechanism 1n a conventional designA of automatic telegraph page printer;

Fig. 6 .is a composite diagrammatic .chart illustrating certain structural differences in the interchangeable warded storage code membersv of the identification signal transmitting drum assembly, and

Fig. 7 is a coordinated timing diagram'to which ref# erence' will be hadduring the courseof the description of operation.

In its preferredembodimenti' this invention has ybeen' designed for applicationto `a commercial type' of page printing telegraph .apparatus having a keyboardy attachment ofthe type illustrated in U. S. PatentNo. 1,904,164, issued in the name of S. Morton et al. The printing mechanism or typebasket of'this apparatus is capable ofmoving bodily from side to side longitudinally of.v a'printingv roller `or..platen..for the purpose.oftproducing-,lines.off

printing: ,transversely on .a rpagegor..webr'offzpaper.: The..

ICE

transmission lof each character vcode v signal results in the: selection of its related type element and is accomplished by the useof a series `of 'tiltable lselectorvanes; This series of vanes is vdisposed across the width of the machines sothat each permutative. settingisimparted yto a series'of; mobile transfer-levers'carried by thetype basket or print: ing carriage..` The.- tiltingfeature of-these selectorv vanes is also utilized in the-establishment offcertain function-` selections by presenting-against :them .selector -ba'rs having: edges characteristicallynotched-and bafed so as-to.- re-rv spond .selectively to. a .relatedplacement of *they-selector.v vanes.

Inv the accompanying drawings the series "ofnselector vanes have been'designated 11 in F ig. 5 while a representative one of the generalvclass of-selectorvbars'y designated 12-also shown in Fig. `5 'Will'.be understoodi topossess: a characteristic. distribution ofv lugs and notches 13 and-14,* respectively.y A-'particulanv selector lever 12x is designed. sothat-it aloneamongothers will vrespond toa certain-t pairof initiating signals, in the instant contemplation-the.. liguresfshift and letter D-signa'ls,wwhich vestablish Ja' selective condition at the called stationapparatus in-a. manner of whiehwill be moreffullyI explainedlhereinafter.

Certain elementsof` the -keyboard portionU of .thisfA station equipmentfare- `illustrated byl fragmentary y-rep'-;- resentations' in Figs. 1 and 2 whereat a 'set-ofy manuallyV operable key -levers havey beenl designated. 15 disposedin parallelalignment .over a transversely dis-:1- posed set ofcodebars 16..- The -code lbars 16- are disposed in .supported lconfinementso that they may beshifted-flonrgitudinally to' and.fro-between alternative extremities: of-f position. .i The uppersedgesof the-.codev-barsi-l. are' characteristical-lyI toothed 'with f variouslyy inclined saw-'.tooth. edges so that'uponthe/depressionof'each-.key lever 151. there will .result an. individual .and '.relateddisposition off? the several codebars16 symbolic of-its'permutative-code"A combination of tmarking and. ispacingsignal.-components`I Atene end the. code bars 16 tare provided.withpairs;- of spacedfcoupl-ingpins 17 orother-v suitable -connecting attachment.articulatingthem with .their transfer .levers-and, l for transmitting..their.respective positional placementvtoj the.y corresponding series of Vtransfer levers 18,- all .pivotediton: a common .axis.19.. and: provided-at ,their .uppermost-ex.- tremities; .with similarly profiled :hook portions i 21.` i and `t with t locking projections. 22...

Inzaccordancev withtheir. related settingV the:.-transfer: levers lSfmay. be :disposed alternatively` yinitheipositionin--tv which.they are y.shown in Fig. 2 whereat vtheir hook por-- tions 21 are disposed to clear the extremities. 23 of-goose-, necklevers 24, which are spring urgedina counterclockwise .direction .about their .common pivot. 25:. When: thus unirnpaired, levers .24 may, bepermitted to. rise.:succes y sively, each during its characteristic intervalin a selectingyl cycle., Otherwise, when the ends -23.of said .goosenecln levers 24 are obstructed by the. alternative .disposition of their related .transfer lever4 when its overhanginghooked.. extremity 21.is moved to the leftof theposition. in Whichw it is shown in Fig.V 2, said levers ywill be prevented fromso.. responding during their characteristic intervals-of .each=.v selecting cycle.

During each intervalwhen a goosenecktlever 24 (Figr 1) is permittedor prevented from rotating eounterclockwise .as described, which time interval isv determined yby. the length and occurrence of its. angular .arc in timing cam 26-of the transmitter cam shaft designated 27, -a dwell portion on the periphery of its related timingcam.: is presented .beneath the follower projection 28 of the... gooseneck levers. These presentations occur successively during. .allocated Vintervals of time in each signal.. cycle which corresponds to a single revolution onthe part. of; shaft'27.y

When, during its signal interval a gooseneck lever 24 is permitted to rotate, its-contact pair 29 vbecomes momentarily closed transmitting an impulse characteristic ofv closed or with current condition, whereas if the lever is prevented from so responding thescontact'par 29nis held open resulting in the transmission of an impulse of the' op-1- posite or no-current signalcond-ition.

For the. purpose of the .present invention thegooseneck.

levers` .24(are. providedgeachwith. an additional probing Y 3 extremity carried by a rightwardly extending and reversedly curving portion 31 disposed after a manner best illustrated in Figs. 1 and 2 whereby to encounter successively the coded ward elements which are carried by the answerback message storage drum 32 pivotally supported on an axial shaft 33.

During the dormant or inactive condition of this answerback signal transmitting accessory the storage drum is so disposed that no blocking engagement is interposed before the probing extremities 31 of any of the gooseneck levers 24. This may be accomplished by establishing a home or zero position for the drum 32 in which the particular radial slot 34 which is then disposed to align with the probing extremities 31 is vacant or unoccupied by a ward bar 35 or if so occupied then by a ward bar 35 having all of its projecting wards removed.

During all other sensing positions of drum 32, or during as many of them as may be reauired for the purpose of transmitting the particular identification message which is to represent any particular called station the ward bars 35 are provided with variously disposed blocking and clearing warded extremities each in accordance with a preestablished code combination which will thereupon resolve the consequent disposition of its related gooseneck lever 24 when its allocated signal interval occurs during the cycle of revolution of shaft 27.

ln order that the automatically transmitted identification signal borne by the message storing drum 32 may be assured noninterference. as by the inadvertent operation of Vthe keyboard during its execution, provision has been made for locking all of the transfer levers against assuming their counterclockwise or gooseneck lever blocking positions. For this purpose a bail lever 37 has been provided also pivoted on shaft 19 and normally urged by a spring 38 into its ineffectual position. Through a train of linkage` which will be described later and which acts upon arm 39 to rotate bail lever 37 clockwise about pivot 19 in opposition to its spring 38. transversely extending bail portion 41 is moved to the right as observed in Fig. 2, gathering all of the transfer levers before it as it does so and retaining them in their unblocking position so that they will be out of interference with the gooseneck levers 24 when the latter are sensing the storage message of the drum 32.

Since both of the transmitting drums 32 of the called as well as of the calling stations are released for rotation by the inquiry signals emanating from the callingr station transmitter. means have been provided for shunting the calling station contacts 29 so that its operation is idle. This is accomplished by providingt a pair of shunt contacts 42 which bridge the transmitting contacts 29 of the calling station. The shunt contact operation is one of conditioning a locking bail under control of the calling station keyboard and then executing its movement by a power stroke of the print mechanism.

A spring-biased operating member 43 is supported in a vertical position after the manner indicated in Figs. 1 and 2 with a transversely extending guide rod 44 passing through an uppermost elongated opening 45 therein and with a common pivotal shaft 46 passing through an enlarged central aperture 47 therein. The opening 45 is of sufficient length to permit operating member 43 to undergo limited vertical motion sufficient to permit its transversely extending operating extremity or interponent 4S to depress the insulation block 49 to close the contact pair 42. Moreover, the aperture 47 is sufficiently wide to permit operating member 43 to be reciprocated sidewardly between the position in which it is shown in Fig. 2 in solid outline and one to the left thereof as suggested by the displaced dotted outline of its operating extremity 48.

A spring 51 connected to a sidewardly extending ear formed integral with member 43 biases the latter member to itsfinactive or uppermost, and to the right. position which is the one referred to as designated in solid outline in Fig. 2. As a consequence of having received an identification inquiring signal there is provided apparatus which will cause the shifting of member 43 to its effective position, shown in dotted outline followed in quick succession by a downwardly depressing action which will cause it to close the shunt contact pair 42.

The shifting and depression of member 43 to its effective position is the result of a selecting operation in the printing apparatus manifest by the rocking clockwise of a bell crank lever 53, one arm of which designated 52 (Figs. 1, 2, and-i) terminates in a lobe which impinges against a lower end or interponent portion 48 of member 43 and another arm of which carries at its distal extremity the spring loading ear 54, the latchable sidewardly bent lug 55 and the letter D code probing bail 56.

This bell crank 53, better visible in Figs. l, 3, and 4, is pivotally supported upon the common rock shaft 46 and is biased by the spring carried on its extremity 54 in a clockwise direction as viewed in Fig. 2. It is prevented from attaining its clockwise extremity except when the transfer levers 1S are so singularly disposed as to present their coded notchings 58 in a transverse alignment which will permit the reception thereinto of the probing bail 56. This clockwise movement is also prevented by the shouldered extremity 59 of a blocking lever 61 which is normally urged by its biasing spring 62 into the position for blocking the latching extremity 55.

The particular selection whose characteristics are such as to dispose all of the code signal responsive elements including the transfer levers 18 in such a manner that they will present their notches 58 in alignment for the reception of probing bail 56 is the second one of a series of signals consisting in the instant embodiment of two code combinations, figures shift and letter D. The first of these signals or figures shift will result in the placement of the transfer levers and their notches 58 in such a manner as to permit the reception thereinto of another probing bail designated 63, Figs. 1 and 2. When this code signal is followed by any other signal than letter D, the one necessary for the selection of the other bail 56, blocking lever 61 becomes restored to its blocking position and thus bell crank 53 is again prevented from movement. This restoration occurs when during a secondary selecting cycle cam 63 restores bell crank 65 followed by a release of latch 7 4 by cam 75, as will become evident.

In order to make certain that the answer-back responsive mechanism be not inadvertently initiated, the conditioning signal-code-combination signals, in this instance two, for accomplishing the selection are advisedly chosen to be such that under normal transmission their succession of occurrence is unlikely. With this in mind, the code combination signals here employed are the figures shift signal followed by the letter D signal. These codes will also be designated as the figure shift letter D selecting combination. or gures-D.

When. at the calling station the transmitting operator depresses his figures shift key followed by the letter D key, he establishes upon his own apparatus mechanically the selection of the probing bail 63 followed thereafter by the selection of the probing bail 56. These selections follow each other and are performed by the short arcuate selecting segments generally designateed 64 and integrally formed with the transfer levers 18.

As a consequence of the selection of probing bail 63, its related bell crank lever 65, Figs. 1 and 3, will be permitted to respond to the urge of its loading spring 66 and move clockwise when during the course of the ensuing cycle the cam follower portion of the lever which follows the periphery of cam 68 rides off the apex which normally holds lever 65 in its upward or poised condition. As a consequence of the aforedescribed movement on the part of lever 65 a sidewardly extending lug 69 (Fig. 4) thereof encounters the extended arm 71 of a blocking lever 61 and since the spring 66 inuencing lever 65 is more powerful than spring 62 it causes lever 61 to be rotated counterclockwise.

Because of the aforedescribed movement on the part of blocking lever 61, two conditions result which enable the subsequent selection of probing bail 56 provided that the ensuing signal is none other than letters 13. First, a sidewardly bent latchable lug 72 integral with lever 61 is moved rearwardly until it is caught and latched behind the shoulder 73, see also Fig. 4, of a spring loaded latch lever 74. Then, as a consequence blocking lever 61 becomes displaced so that its blocking shoulder 59 is withdrawn from the path of sidewardly extending lug 55 already described as being a part of the selectable bell crank lever 53. This clears the path for the second probing bail 56 and permits that element to move into the alignment of notches 58 in the transfer levers 18 when the ensuing signal D is received.

The cam shaft 27 ordinarily rotates in single revolution cycles, being released for each revolution as a result of the operation of any key lever by a well known trip rmechanism coincident with the transmission of each code combination, .signal The.` -cams carried on .its closely spaced clusterf.include' ..those.. which time .the.goosene ck levers,24-during.360 .degrees of rotation.4 An. additional camrdesignatcd 75..carried by thisshaft has litsapex dispsed.so. .as .to rbeeflectiveat 180 degrees from starting position...L Its function is to. actuatelatch lever 74 against.

the inuence of a return spring for the purpose of. releasing.,blocking level-` 61. y WhenV this .happens ,during the cycle in.which fgures.shft bell crank lever, 65 .has beenV selected, ,the release 'of latch .lever 61. is prevented. befcause;.said.lever.61 continues to beheld in .its counterclockwise or unblockzpositionby reason of the engagement of bent-over `lug 69.0f .lever 65 with the extended arm.71 of the blocking lever. Meanwhile cam.75 passes onandlatch .lever 74 resumes its latch position..

At .the conclusion of each cam-shaftcycle, a .cam.68'on shftlrestores. bell crank lever 65,.freeing its retaining,

eifectupon .latch lever 61.so1that upon a subsequent rotation .of-shaft 27, cam= 75 acting on latch lever 74 will releaseblockinglever 61 to its normal or blocking position asrcgardsthe secondary. selectable bell crank 53. From thisit .is'..to .be.understood that blocking lever.61- isnormally.,.disposed.to prevent. the selective response of secondary` selection bell crankv 53 unless :the signal thereof, namely D, which would prepare the notches 58 for the reception of its probing bail 56 is precededby the assigned preparing signal which will. operate towithdraw the blocking:,lever...61.. When, therefore, the two chosensignals succeedeach other. improper order, bell cranklever' 65 is operatedasa consequence of the selectionof Yits probing.

bail .63,latch and. blocking lever 61 is vgotten .out of the4 way, letter =D .selecting bell. crank 53 is .thenpermitted to.respondto its signal.

After .bothof these signalsfhave been received at the,

calledstat-ion, va set-.of preparatory'conditions.k is :established, assuringfor the uninterrupted exclusive allocation.

of Athecommunication channel to the automaticanswerbackmechanism by effecting a .locking up.of. themanual-- keyboards .aL-.both callingy and called stations, `and.by.al

shiinting. of thecalling station transmitting contacts 29 so thatitsdrum rotation. will. be idle or ineffective.. Thisis accomplished in the following. manner.

As a resultof the operation of bell crank lever 53-'atv the .calling station its arm 52 displaces the interponent 48:

ofinember..43, after. the manner alreadyvdescribedresulting-.;in..the preparation. for closure of contact pair 42.l Upon this limited rotation of vlever 43 `in a clockwise di-y rection, the lever 43.will be latched in its clockwise position:by.a latchl leverf125 pivoted to the frameat 126 and biased counterclockwise by a spring 127 .through the coactionofnotch 124 of lever 125 and lateral portion.123 fof lever 43.Y As will presently appear', the closure of con.. ta'ets .42 shunts/the calling stationtransmitter contactsl soV long aslmember 43 continues to be depressed. The initial actuation or depression .of member 43 is brought abouty as a result of its being shifted from the right-hand orsolid outline positionto .the left or dottedoutline position-re-A specting the showing of this member 1n Flg. 2,ifollowed. bythe downward movement or depression of member y43'y byzlapoweradjunct of theA printer unit which will now be described..

When the keyboard operator at the calling station actuates his. identification inquiry signals, -gure shift .and

D,? these codes are impressed upon the receiving distributor at the desinationstation as well as in his own printer unit.A As a consequence, the selector vanes 11 (Fig. 5) become placed into a characteristic disposition because of the six vanes, live respond to the code combination for the letter D while the sixth is previously conditioned by the preceding figures shift code combi somewhat weaker than spring 77 so that lever 81 rotatesslightly around its pivotal. center 83 presenting a shoulder 84-.intosthepath`of .theuoperating bail .85- which isfpart of?? therpower-Sfdrivenv mechanism: ofthe printer unit :zand core.-

responds...toflnailt `188..;i1lustrated .in the referred-ttor.'Patent; No.v :1,904,164 .2 Thevoperative; stroke. of -.bail .85; isffrightf.. wardasviewed .in.Fig..j so that uponfengaging shoulders` 84 of .companion lever. 81 the latter member-:will The. shifted rightwardly` as permitted by the elongatedslot` 86 imparting Igcounterclockwise rotation to fthe bell l -crank lever 87. Y I

Thispower stroke causes .-bel1.. ;rank.2leverl a 87-Y torwork: against. the.. influence of its .restoration Vspring 881and .tof fo'rceablyv depress.thev.,headl` of lan adjustableffscrew`89 thereof against the projecting lobe 910i la dual-purpose4 lever 92 which is-vpivotally.. carriedon.arodf93-that;juts1 out .of the.v side frame... This power stroke- =causes. levera- 92..to be rotated counterclockwise about-its pivotal-:centenv 93 engagingwithrits shoulder. 94 the .recent-ly.displaced-sine. terponentk 48 .of .thrustfmembeiz 43y .and supplyinggtheumo-n tion necessary to :cause it. to actuate-and close the contact. pair 42. A

Asa further. result-of .thecrotation Lof .the lever-f92fsa lobed extremity. 95 .encounters .the\arm..39-of.baillever. 37, rotating the y latter.. member --clockvv.ise. asffviewed Fig.V 2 about its. pivot 19andgatheringwith its.bail-.:rod` 41 all of the transfer. levers 18 topresentthem out-.ofthe path of the blockingshoulders v23.of.thegooseneck levers, 24." This prevents the keyboard from being h.operated since kthe displacement ofA thetransferlevers 18.throughy their -`articulation as at 17 withthe code..bars .16'. results:-

in an effectual .locking of the, latter members in their; le'ftf -A hand position as viewedin Fig.2.

Beyond `the bail rod 41..is. a. clutch '.trip continuation. designated .40. This elementconstitutesa-an offset portion. of tneA bail.' 41v 'disposedto engagea,.projection:40kz:ofa bell crank lever'40b, which will .permanently depress., the..

clutch trip r arm 132 so, that the transmitting cam shaft 27...

willhave. continuous rotation .duringthe period. of.- time. occupied by the answer-back signal. Thedurationviof this period is concluded whenthefmultiple purposelever.. 92y is released from its Powerstroke actuatedposition upon. the termination of the message identicationor.. answers, back ,cycleby a lug projection. 117 (Fig. 1), 'which'acts upon latch Flever l99 to rotate ,lever 99 to'. release Vlatchfl projection 98 -from shoulder. 97. Whenztheflever 92 is thuspermitte'd-to return to. its yzclockwiseposition .(as. shown in F1g. 2),lthen Vthe member 43 isfreetofreturn,...

under the inliuence lof its :spring 51 to.itsA upwardand..

connterclockwiseposition (also shownin Fig. 2).

However, this return Lof 1everf.43. is acnievedin .the followingmanner; It willbe.recalledthat when lever.

43 was rotated to. p resent itsportion .48.from the-solid; line `totheidotted line position (Fig. 2)',` thelatchfleverfI 125 coacted with.l portion123 to hold` lever 43Min its..

clockwise position.; Then,.,when lever AV43 wasdepressed. the portion 123` wasretractedfrom.shoulder-.124 topermit.. lever .125 1o rotate. aboutfpivot 12.6 under the ,.inuenceof spring 127.? until.lever.. 126 wasl arrested by the stop:

128..xedttoatheframe of .the` machines It is to be noted here ,tliatthe distancef`'..(Fig.-,2) between the.inter,` ponent ASLandrthefshoulder on. insulating block ...49 is until interponent n.48..takes upthe. clearance,100land en.y

gagesthe shouldenfof, block, 49, at which time thelat-rV eral. portion -123.;'.willbe moved out of register. .with the..

latch shoulder. .1241and instead engage vtheflower edgef oftheleverarm .of.lever..125. Then, upon-the.v return..

of, Amember ,43 to its :upward v position under the. .influence of spr1`ng, 51, .lever-.` 125 will, be rotated tothe position..

This placement-.of lever4 921is prolonged after the power.. stroke is withdrawn.by,ralatchingarrangement.. A4 de.. pending arm.. 96 .of .leven 92`-is provided' with a latching... tooth 97`Whichbecomeslodged behind a lug.,98-which. jutssidewardly' from a la'tchilever 99 spring urged linLa coun'terclockwise directionabout its pivot on shaft 46.Y

Afterthestorage drum. 32 .has completedan' angular.'

amount of rotation, equivalent to a station identification message cycle, which 1s tosay, after it has presented all Z4` lit willf'arriveatfa position which is-theend off-the;

stationfidentification--rnessage;which is the one'in which' itl is -'shqwnfi.n.-Fig.i2 whereatia .particular one of the code barsi designated .i103 eWhserforemost-iextremity: 11-7- exe:

7 tends farther than do the other code bars 101 and 102, engages with such extremity the end of lever 99. This rocks the latter member counterclockwise about pivot 46 and releases latch tooth 97 and consequently lever 92 to normal condition.

From the foregoing, it is observed that it is possible to embrace one or more answer-back messages (such as station identication) on the drum 32 depending upon the positions of the extremities 117. For example, if an answer-back message comprises approximately 21 characters, only one extremity 117 is needed. Moreover, if an answer-back message comprises seven characters, then three extremities 117 are used (seven characters apart). In the former example, the drum 32 will make one complete rotation per message cycle, and in the latter example, the drum 32 will make only one-third of a complete rotation for each message cycle. Furthermore, the length of answer-back messages controlled by the drum 32 need not be of equal length, but instead may be of variable length as determined by the angular positionments of extremities 117. Of course, the total number of character positions on drum 32, although indicated in the present embodiment as 21 positions, may be any other number of angular or character positions within reasonable limits.

It may be noted that multiple purpose lever 92 receiving its power stroke from the operating bail of the printer moves into its counterclockwise extreme position and is latched thereat by latch lever 99 establishing electrically a shunt condition for the transmitting contacts 42 that shunts the calling station transmitter and also that it effectually locks the keyboard mechanism and prevents the transfer levers from interfering with the performance of the gooseneck levers 24 during the time that the stored message transmitting drum 32 takes over.

There is yet another function which is performed by the multiple purpose lever 92 which takes place as a result of its initial rotation counterclockwise and this will now be described.

At 105 there is pivoted to the side of lever 92 a spring biased pawl 106 whose single feed tooth 107 is disposed to engage the sidewardly extending extra length of one of the code bars 101 presented in the particular position for this purpose. At this stage in the cycle of drum 32 also referred to as one of its initial station identification positions, the bar 103V has released lever 92 from its preceding lock up condition. As a result the counterclockwise rotation of lever 92 acting through pawl 106 imparts a single step movement to drum 32 moving it from home position to its number one transmitting position. This is the sole purpose of pawl 106 since at all other times the feeding or advancing of the transmitting drum 32 is a function executed by a principal feed pawl 108 pivotally carried on a stroking arm 109 and biased in a counterclockwise direction by a spring 111.

Stroking arm 109 is pivotally carried on shaft 46 and includes a follower projection 112 which rides the peripherv of a cam 113 provided with a single apex for imparting reciprocal motion to said arm 109 in opposition tn its return spring 110. Each of the coded bars 101, 102 and 1.03 is provided with sutiicient length in the direction which extends into the path of feed pawl 108 to be engaged therebv. with the exception of one bar that happens to be disposed radially in alignment with the tooth of the feed pawl S at the time that the drum 32 is in its home position. This particular bar is purposely foreshortened. however. so that upon arriving at home position the further actuation by cam 113 of arm 109 and pawl 108 will cease to advance the rotation of drum 32. the latter having completed a full cycle of rotation. therwise stated. cam drum 32 is brought to rest after the full message has been transmitted which comprises all or as many of the bars 101, 102 and 103 as are devoted to the answer-back objective.

Referring now more particularly to Fig. 6 attention is directed to the structural variations between bars 101, 102 and 103 by reason of which the stepping of the drum 32 is regulated with regard to initial stepping pawl 106 and normal feed pawl 108, Figs. 1 and 2. Also it will be explained that detenting is accomplished by the action of a detent arm 110. The general class of bars is represented by the one designated by the reference numeral 101. This bar is provided with an extending portion 114 which protrudes beyond the left drum disc 115 drum from one position to the next.

so as to lie in the path of start or stepping pawl 106.` Although pawl 106 is etfective only during the initial stepping operation, the extending portions 114 on the remainder of the bars will serve merely the idle purpose of camming or clicking pawl 106 out of the way as they proceed in a step-by-step manner rotating counterclockwise as observed in Fig. 2.

A certain one of the bars such as the one designated 102 is foreshortened as at 116 so as not to extend into the range occupied by the conventional feed pawl 108 when the drum 32 arrives at its home or zero position. This is for the purpose of rendering further operation of pawl idle and for bringing the drum 32 to rest. Yet another bar such as the one designated 103, see also Fig. 2, is provided with a somewhat oversized projection 117 by reason of which it may positively engage the end of release latch 99 just as the drum 32 reaches home or zero position. The several bars are contained between two or more radially slotted discs 118 and 119, Fig. 1, Whereat they may be securely located and retained in any convenient manner as by encirclement with hoop or garter rings. Accordingly, for the purposes of changing the stored code message it is but necessary to spring the garter rings out of position to be able to remove any one or more of the coded bars or to interchange them as may be preferred.

Message storing drums constructed in accordance with these teachings possess among other advantages facility of adjustment, interchangeability of message characters and regularity in feeding since the number of steps which constitute each cycle of rotation is thus maintained in conformity with the number of code bars and since the ends of the code bars themselves constitute the engageable means whereby the feed pawl advances the code If it is desired to have a code drum with, say, twenty code signals, then the dividing up of the periphery to accommodate twenty code bars concurrently establishes the twenty steps necessary to complete a cycle of revolution. In this way, even the problem of introducing variations in the number of code signals becomes singularly simplified. All that is required to make an established number of signal positions serve for any lesser number of signals is to supply blank insert bars or bars with the code projections entirely mutilated or removed so that the signal transmitter will issue a sequence of blank signals to ill out the balance of the message cycle.

In this connection attention is again directed to Fig. 6 where the reference numeral 101 designates a typical storage blank from which a code combination bar may be made for the metal storage transmitting drum according to the proposed features of construction. This bar is provided with tive upstanding ngers or lugs 121, preferably rendered frangible from the main stock or body of the bar 101 by scoring or otherwise suitably weakening as at 122. This may be accomplished during the original stamping of these members or subsequently as by punching or milling, it being of importance to note that any practice of weakening need be but relatively minor so that during setting up a mechanic may by bending any one of the tabs 121 with a pair of pliers break them. oif the body stock according to any pattern of distribution required in accordance with a particular coded message. In this way, since the message characteristics are borne by inexpensive sheet steel stampings which may be quickly and easily replaced or interchanged during 'field adjustment the subject matter of the metal storage drum, whether it be for purposes of identification or other, will be observed to lend itself quickly and easily to revision or reformation at a minimum of cost.

There is also taught in accordance with the provisions of this invention improved principles of telegraph supervision whereby in response to certain types of control station initiation a remote printer may be disabled for the duration of a precise interval of time. In the instant case such control is coincident with the transmission of the inquiring or who are you signal to the called station. This has been done by devising a selectable auxiliary mechanism which is made responsive to a certain plurality of code combination signals when transmitted in a precise order. In the particular disclosure the ultimately operated or selected device is the bell crank lever 53 whose downwardly extending arm 52 diS- placesfihe; interpellent: 48 to f 'a posit'rzm;:,vvhereatritz will. receive :a depression stroke: by;thersl1oulde1f94l of the-.muh tiple purpose lever192 powerstctuatedfby the;printerzbail..

It .islto be observed fronLFigs.V .1 and 3 thatvthe de.y pressibletmember i43.:has..been provided..witha side-,. wardlybent lug 123. which. servestwo purposes. r On the: oneshand, this.lug .serves asjantattachment earv for the, return spring ,51 whichraises the rody .43 jto its normal. level .shown asqin Fig. 2, whenzthe multiple purpose lever. 92is.restored. Also this spring urges rod 43 toward the. right as viewedin .the Figsnl and-.2 restoring-,it :to-.its neutralor ineffectual. position .clear of shoulder 94.

Inaddition lug-123 .provides an 'engagement shoulder: for. the latchingtooth A124;'ofg`a .latch pawl 125 pivoted at 126 andybiased. in .a -counterclockwise directionby-a spring 127. When the. interponent.,48 ybecomes-displaced leftwardly, Fig. .2, because. of the: action tof. downwardly. cxtendingarm: 52 of bell .crank,53 the toothed latch lever, 125:.'immediately engagesthe -sidewardly extending lug 123;.holding the. depressiblenoperating member y43 in;its shifted or dotted outlineposition asfobserved in Fig. '2- The'11closing fof. the contact pair. 42 ldoes vnot become accomplished, however,.until. the power stroke hasbeen transmitted thereto through themultiple purpose lever 92... Release of latch lever. 125 is` accomplishedin. a manner previously described at the conclusion of the answer-back message cycle when restoration latch99 is actuated by an answer-.back message terminating bar 103 having .the enlarged lug. 1117.' j

Operation located at both the calling and-called stations/will be provided, each having 4keyboard transmitting and .printing mechanismauxiliary equipment such as that-disclosedin Figs. 1 and 4. The calling operator Iwill.initiate the answer-back `cycle by iirst depressing the` gures shift keylever 15.` This will 'resulti'in a shifting-'and consequent placement of the keyboard transmitterl codebars 16 'as well vas a correspondingl placement in vthe. transfer levers 18'.V As a consequence, the selecting-notches' 58'.v

in the segments' 64 of the specially provided transfer.-

levers 18 will present a clearance to the figures shiftl.: probing bail 63 while'responding inlits customaryl manner clutch releaselever 131 will befdepressed voperating the trip lever 132 and 'causing to\ be.l withdrawnv itsdeclutching tooth 133. Thereupon; the clutch elements 134 under inuence of their spring 135UWill come together imparting rotationr from lthe continuously rotating shaft 136fto the main cam' shaft 27.I This rotation will in'- clude lbut a single cyclev of revolution-because of the characteristic mannerL in which de'clu'tching lever 133 'ist permitted to resume its yeffective declutching 'position' after each revolution.-

As a consequence of the rstcycle of rotation on ythel part ofcam shaft 27, the apex of cam 113 will ride out from beneath the follower projection 112 of arm^109 (Fig. 4) 'imparting a single stroke actuation to stepping pawl 108 but this response will be idle" because, as has been said, the feed tooth of pawl 108 is at thisitime disposed to engage the extending'endsof the drum barrel 32 whereat a coded bar 102 is positioned which v'has no protrusion longitudinally beyond thefstorage 4drum disc 119.

In unison with cam 113, cams 60 and 68 will rideoutfrom beneath their follower projections of bell crank levers 65 "and 53, respectively', but of these, only lever 65 being presented with selecting clearanceat notches 58 will undergo clockwise rotation after the manner indicated by timing chart curve 65 andasa result, the side- Wardly extending lug 69 of lever 65 will rotate blocking lever. 61- counterclockwise causing itto be latched Awhen thexsidewardly bent lug v72 thereof becomes lodgedtbehind the shoulder 73 of latch lever `74. The iigures shift bell crank lever 65 continues to remain in its selected Str.

positionfso thaneven though latehleverfreleasing geant.

75.pr.esen tsits..-apex.3at180 degrees .during.th e coursezof this.cycleiof rotation and tripslatch lever 74, blocking.- lever.,61.,continuesztoV remain -in lits ,-unblocking .position and the apex of latch trippingcarn 75 passes -by withouty liftibell `crank levers 53 and 65, -the former to a partial,

degree of movement only,but they latter throughoutits. full return motion causing to be withdrawn the blocking'.v lever .operating lug- 69 fbutvblocking ,lever` 61. continues-u to,;be held inits unblockingposition. because meanwhile,- latch lever..74 has been-restoredto itsjelfective position.

Thei -calling;;operator=.wi1l now depress the keyboard; lever 15'.;which '.pertainsto alphabetical character. D. andwagain clutch elements ,134 will be trippedeso that driven cam shaft 27 undergoes a -second cycle ofsrota-vtion; Meanwhile, the characteristic placement which;v has been impressed ,bygkey lever 15 of .D` uponithe. codel bars 16 presents a clearanceof notches 584 to .the probing bail 56of the D bell crank leverl 53. As. a consequence of ridingout.V on the part of cams 601.and 6Swfrom beneath their.y bell-crank levers, lever 53 willy nowbepermitted to rotate clockwise as viewedvin Fig.;2., Atythis time the selection will be permitted for the further-.reason that its sidewardly extending lug is not-v impaired by-theblocking.lever 61 which remains -in itsy unblockingposition as has .been described This ,movement ofthe. letter D selectable bell crank,4

53 about its pivot 46 is compelled by the relatively strong` springattached to its. arm S4'Whose tension is sufficient to.overcorne. they restoringspring 51 of depressible meme: ber,43 and asa consequence'thef.downwardly extendingV arm SZ-ofgthe aforedescribedbell crank will cause to'be displaced-theinterponent 48.from its solid to its dotted. outlined .positions ;as viewed inFig. 2. Following this displacement, latch lever125 .will slip'behind the sidewardly -extending;,lug=,,123 of-l member 43-and ,thereby servesftoretain itgin its-ready condition even though,v bellcrank-.levery53 is promptly restored to its unselected-` conditionfatthe;conclusion of this cycle bythe rreturn of,- its restoration cam of shaft 27.

Meanwhile. as.r a result, ofthe normal; responses of thentranslnitting. gooseneck levers 24 acting. upon their;` transmitting contacts-29; ftherel will, becaused to` issue-,-

ou-t,over.:.the; line; connecting the .two stationsy the conv ventional..veunit/.permutation code signals which per-jr.

' -.tainto ltheiigures shift code..-as\ a consequence of thev operation Yof-Athe guresshift key lever15,l andl that of the let-terry D. codeas aconsequence .of -the operation.. of,.the.letter; Df key-lever 15..

Atvboth, the .calling.andcalled stations,.these signalswill produce their customary effect uponthe selectormechanism of the receiving printers. Accordingly,- the selectorvaneslLFig. 5,'will become.-place,d.in a characteristicmannerpwhich will'afford aclearance-to the specialtfunction bar 12 `sothat thatmember will rotatecounterclockwise under theiniluence of its spring 77 lift, ing its blocking lobe 78 from the plate 79 of a companionlever 81.. Whentherefore, duringthe course.of conventional. operation each-printer power bail receivesf its motordriven stroke rightwardly, as viewed'in Fig5, it..will engagefthe shoulder 84.off companion lever 81v rotating. bell ,crank lever 87 in a counterclockwise direction as viewedin thisillustration -and imparting a power. stroke through its adjustable ,screwl head 89 against the. lobew-,extension91 of multiple purpose lever 92.

At lthe calling station .the counterclockwise `movement ofmultiple ypurpose lever :92,V Fig.. l, will depress the.

shunt contact operating ,member.43",. closing the ContactA pair 42.,. which shunts outthe transmitting contacts 29 of Atthecalled the .callingstation keyboard transmitter. stationzthis conditionwill not-obtainbecause its inter-r ponent 48' willsnot havebeen .shifted to elfective position. Lobe` projection 95. will rockubell crank lever 37 clockwise: about its pivotal. center 19 sweeping allof the. transfer levers 18 'clearof theirblocking position with crank 37 its clutch controlling extremity 40 will rotate bell crank 40h bodily withdrawing the declutch element 133 with the result that clutch members 134 will remain coupled for repeat cycle rotation for the duration of the answer-back signaling period.

Because of the action of latch lever 99 the power stroke actuation of multiple purpose lever 92 will remain effective until the transmitting drum 32 has completed a full cycle of rotation and until its extra length of code bar 163 has engaged latch lever 99 to release the multiple purpose lever 92 to its normal condition. During the answer-back period the rotation of transmitting drum 32 at the calling station and the sensing operation of its gooseneck levers 24 will be idle, however, since all of the transmitting contacts 29 at that station will have been shunted out on account of the closure of contact pair 42. At the called station, however, the action of its multiple purpose lever 92 Will have no effect upon interponent 48 because no local keyboard operation will have been executed to cause the shifting of interponent 48 from its ineffectual to its effective position. v

During the course of answer-back signal transmission jockey levers 110 at both stations spring urged in a counterclockwise direction as viewed in Fig. 1 will successively place behind each code bar extension 101, 102 and 103 and prevent the clockwise rotation of drums 32 as the stepping pawls S successively reciprocate between feed and return conditions. Also at both stations stepping pawls 106 will remain depressed and be successively cammed out of the way by the oncoming sideward extensions of the code bars without producing any consequent effect.

At the conclusion of the answer-back transmission from the called station, both transmitting drums 32 will reach their answer-back end position and will cause to be released their respective latch levers 99 for unlatching their respective multiple purpose levers 92, so that as a consequence, the two stations will remain connected for purposes of further normal communication one with another if the answer-back identification signal verifies the propriety of their connection. Otherwise the two stations may be disconnected at the election of either stations operator in accordance with the conventional exchange apparatus.

While the present invention has been explained and described with reference to particular details of construction and operation, it is to be understood, nevertheless, that numerous changes and modifications are susceptible of being incorporated without departing from the essential spirit or scope of the invention. Accordingly, it is not intended to be limited in an understanding of this invention to the particular language employed in the foregoing description nor to the pictorial illustrations in the accompanying drawings, except as indicated in the hereunto appended claims.

What is claimed is:

1. A metal storage transmitting apparatus comprising a cylindrical support member mounted on a shaft for rotation, the peripheral surface of said member having longitudinal slots parallel to its axis of rotation and said slots being spaced circumferentially about said member, a plurality of signal code bearing inserts each adapted to be positioned in one of said peripheral slots, said inserts having portions extending longitudinally beyond its said cylindrical periphery, a feed pawl at one end of said member, powered means for imparting reciprocal movement to said pawl, said pawl having a tooth for engaging each of said extending portions for thereby imparting step-by-step rotation to said member, at least one of said inserts having no extending portion to be engaged by said feed pawl whereby to establish a zero position for said cylindrical member, and a start pawl engaging said inserts in another circumferential respect, said start pawl including reciprocating means whereby to impart an initial step movement for advancing said cylindrical member over its said zero position.

2. A storage transmitting apparatus comprising a rotary cylindrical member having in its surface radial slots parallel to its axis of rotation, said slots being shallow and spaced circumferentially, a blade adapted to be positioned in each of said slots having an individual distribution of code signal projections and including a portion extending longitudinally beyond its said cylindrical member to constitute a feed pawl engagement, a feed pawl carried at one end of said cylindrical member capable of reciprocal movement and having a tooth for engaging each of said extending portions for thereby imparting a step movement toward the rotation of said member which corresponds to the radial spacing between consecutive signal storage blades carried thereon, at least one of said blades having its extending portion altered to avoid engagement by said feed pawl for thereby establishing a zero position for bringing to rest the stepby-step movement of said rotary member, and a start pawl engaging said inserts in another circumferential respect, said start pawl including reciprocating means whereby to impart an initial step movement for advancing said rotary member over its said zero position.

3. A stored message transmitting drum comprising a rotary member having a substantially cylindrical surface in which are formed longitudinal slots, said slots being equally spaced circumferentially about said member, a plurality of insert elements each adapted to be secured in one of said slots and including control portions which extend longitudinally beyond said cylindrical member, a feed pawl at one end of said member for controlling the step-by-step movement of said member, a rotary power source for operating said feed pawl, clutch mechanism for connecting said source to said feed pawl, and a portion on one of said insert elements extending to engage said clutch mechanism for thereby arresting said feed pawl and through it said member after the completion of a predeterminable degree of rotation.

4. In a metal storage telegraph transmitter, a principal cylindrical member mounted for rotation on its cylindrical axial center and having on its periphery a plurality of radially spaced receiving slots, a plurality of inserts each receivable within one of said slots and including a portion extending longitudinally beyond said member, a feed pawl for engaging said extending portion of each insert for imparting a step of rotary movement to said member for each insert carried thereby so that the number of radial steps conform to the number of inserts in said storage member, and encircling means confined in circumferential grooves of said member for embracing and retaining said inserts.

5. The combination set forth in claim 4 in which said encircling means is a springably removable girdling element which engages each insert whereby there is afforded replaceability and interchangeability of said inserts.

6. The combination set forth in claim 4 including a peripherally protuberant portion on at least one of said inserts, and a control mechanism for said feed pawl disposed to be engaged by said protuberant portion for leffecting the cyclic supervision in rotation of said mem- 7. In an automatic stored message transmitter, a principal member mounted for rotation and having a cylindrical periphery formed with a plurality of radially spaced and longitudinally extending insert receiving slots, an insert for each of said slots and including a portion extending beyond said member, each of said inserts having frangible projections whereby it may be conformed to the code characteristics of a telegraph symbol, a feed pawl for engaging said extending portion of each insert for imparting a step of rotary movement to said member so that the number of radial steps conform to the nurnber of inserts in said member, power means for actuating said feed pawl, clutch control means for regulating the application of said power means to said feed pawl, and removable encircling means confined in circumferential grooves of said member for embracing and retaining said inserts.

8. The combination set forth in claim 7 including a peripherally protuberant portion at one or more of said inserts, and a control disposed to be engaged by said protuberant portion for operating said clutch control means.

References Cited in the ile of this patent UNTTED STATES PATENTS 606,356 Norden June 28, 1898 1,100,413 Wotton June 16, 1914 1,164,737 Mead Dec. 21, 1915 2,496,183 Thias et al. Ian. 31, 1950 

